IF MATHEWS ISN’T BEING USED, WHY KEEP HIM?

Broncos at Chargers

We can reserve judgment on whether the Chargers should keep Ryan Mathews for the final year of his contract. But we can certainly wonder now why they would.

If he’s going to be a decoy, at best, and more often a spectator in crucial moments, just what use is the former No. 1 draft choice who has already cost the Chargers almost $17 million since they moved up 16 spots in the 2010 draft to acquire him?

Mathews played 15 of the Chargers’ 66 offensive snaps on Sunday in Washington. He carried the ball seven times — just once in the second half and not on any of those fateful three plays from inside the 1-yard line at the end of the fourth quarter.

And no one will say why other than to say they won’t second-guess any play-calling.

Preposterous.

I don’t care what the Redskins were doing on defense.

Mathews averaged 4.9 yards on his seven carries. The kid is running downhill as well as he ever has. He was coming off two straight 100-yard games.

When he’s not fumbling — and, you know what, it’s time the Chargers assume he’s not going to — Mathews can get the difficult yards.

His season rushing average of 4.1 yards is not inflated by long runs. Mathews has just nine runs of 10 yards or more.

There is not another running back in the NFL this season who has carried more than 100 times and is averaging more than 4 yards with so few 10-yard-plus carries. For whatever deficiencies he has, Mathews is one of the best at not getting caught behind the line of scrimmage, turning potential losses into acceptable gains. The six times he has lost yardage this season are third-fewest among the two dozen who have carried at least 100 times.

That he has two rushing attempts inside the opponent’s 10-yard line this year is unfathomable. It also helps explain the Chargers being the NFL’s third-worst team in goal-to-go touchdown efficiency (8-of-16).

Let Mathews try to run through the middle, behind Le’Ron McClain and/or the right side of the line. Let Mathews leap over the line.

LaDainian Tomlinson does a weekly segment on “The Darren Smith Show” on The Mighty 1090 (a U-T San Diego media partner, by the way, but pretty much everyone is these days). In a fantastic segment with Smith on Monday, Tomlinson said he would have acted “like Dez Bryant … on the sideline in a tirade … I think that’s the way I’d be acting if I didn’t get the football down on the goal line.”

First, I don’t believe Tomlinson would have shown anyone up the way Bryant did to Cowboys quarterback Tony Romo when Bryant wasn’t getting the number of passes he thought he deserved.

Second, we must acknowledge a monumental difference between the expectation that Tomlinson would get the ball on the goal line and that Mathews would.

Tomlinson’s 145 career rushing touchdowns are second in NFL history to Emmitt Smith’s 164. Of those 145 TDs, 114 came from inside the 10-yard line, 79 from inside the 5 and 38 from the 1.

Few have been as automatic as LT. It was if the end zone was a magnet to him.

At times, yes, the goal line has seemed like the Great Wall of China to Mathews. Even though he’d run just 28 times inside the opposing 10 in his first three seasons, he had lost two fumbles there.

Still, though, this pearl from Tomlinson about the situation the Chargers were in Sunday applies to Mathews as well: “That’s the perfect time to show confidence in your back to say we’re going to give you the opportunity to win football games for us.”

Or not.

And if not, save the $1.48 million in salary and the nearly $1.5 million in cap space and find yourself another lead back for 2014.

Except for that run out of bounds late against Indianapolis two weeks ago, it sure appeared recently that Mathews was going to play his way into being secure. Now we’re left to believe that the Chargers have no interest in using him in ’13, let alone ’14.

Tomlinson also said Mathews has been in the league long enough that he “doesn’t have to stay quiet.” Mathews, however, is not that player. He said he expected to get the ball when he went in on that second down from the 1 on Sunday, but added that he did not say anything to any coach afterward.

“I feel like I could (score), but we have a lot of guys that can do it,” Mathews said. “… I’ve just got to keep working hard. My time will come.”